JP2831686B2 - 3D object modeling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a three-dimensional object forming method using a three-dimensional object forming thermosetting resin composition.

[Problems to be solved by conventional technology and invention]

Generally, a model corresponding to the product shape required at the time of mold production, or a model for contouring control of a cutting process or a model for an electric discharge machining electrode is manufactured manually or by an NC.
It was performed by NC cutting using a milling machine or the like.
However, manual machining has the problem of requiring a lot of labor and skill.In the case of NC machining, it is necessary to create a complicated machining program that takes into account replacement and wear for changing the shape of the blade edge. In addition to the above, there is a problem that further finishing may be required in order to remove a step generated on the processing surface. Recently, a new technique for overcoming these problems of the prior art and creating a new model for forming a complex model and various fixed objects for thermoforming three-dimensional objects for mold making, copying, sculpture electric discharge machining, etc. Development is expected.

The thermosetting resin for three-dimensional modeling has excellent curing sensitivity by heating, low viscosity, low volumetric shrinkage during curing, excellent mechanical strength of the cured product, and self-adhesion. Various properties are required, such as good properties and good curing properties in an oxygen atmosphere.

The thermosetting resin includes acrylic resin, urethane resin, phenol resin, furan resin, xylene / formaldehyde resin, ketone / formaldehyde resin, urea resin, melamine resin, aniline resin, alkyd resin, unsaturated polyester resin, epoxy resin, etc. However, none of the commercially available products so far has been optimal as a thermosetting resin composition for three-dimensional modeling.

[Means for solving the problem]

The present invention has been found as a result of intensive studies on various characteristics required as such a thermosetting resin for three-dimensional modeling.

"An object of the present invention is to provide a three-dimensional object forming method using a resin composition most suitable for a thermosetting three-dimensional object forming system.

The three-dimensional object forming method of the present invention comprises, as an essential component, (a)
The following general formula (I) is used as a thermosetting cationically polymerizable organic substance and (b) a heat-sensitive cationic polymerization initiator. [Wherein R ₁ and R ₂ are the same or different, substituted or unsubstituted hydrocarbon groups, and R ₁ and R ₂ may form a ring. A represents the following general formula (II) or (III) (Here, R _{3 to} R ₆ are a hydrogen atom or a substituted or unsubstituted aliphatic group, and at least one of R _{3 to} R ₆ needs to be a substituted or unsubstituted aliphatic group. R ₇
To R ₉ are a substituted or unsubstituted aliphatic group, and any two of R _{7 to} R ₉ may form a ring. ). Further X ^- is a non-nucleophilic anion. Step 1 of placing a thermosetting resin composition for three-dimensional modeling containing a sulfonium salt represented by the following formula in a container: curing by applying heat energy to the surface of the thermosetting resin composition for three-dimensional modeling to obtain a desired thickness Step 2 of obtaining a first cured product, Step 3 of forming a layer of a thermosetting resin composition for three-dimensional modeling on the first cured product, Three-dimensional modeling formed on the first cured product Step 4 of curing by applying thermal energy to the surface of the layer of the thermosetting resin composition to obtain a laminate in which a second cured product having a desired thickness is laminated on the first cured product, Step 3 in which Step 3 and Step 4 are repeated one or more times. The (a) thermosetting cationically polymerizable organic substance which is a constituent element of the present invention is a cationically polymerizable compound which is polymerized or cross-linked by irradiation with energy rays in the presence of (b) a heat-sensitive cationic polymerization initiator. In, for example, an epoxy compound,
It comprises one or a mixture of two or more of a cyclic ether compound, a cyclic lactone compound, a cyclic acetal compound, a cyclic thioether compound, a spiroorthoester compound and a vinyl compound. Among these cationically polymerizable compounds, compounds having at least two or more epoxy groups in one molecule are preferable, and examples thereof include conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. Can be

Preferred as the aromatic epoxy resin are polyphenols having at least one aromatic nucleus or polyglycidyl ethers of alkylene oxide adducts thereof, such as bisphenol A and bisphenol F.
Or a glycidyl ether produced by reacting an alkylene oxide adduct thereof with epichlorohydrin, or
Epoxy novolak resins.

Preferred examples of the alicyclic epoxy resin include a polyglycidyl ether of a polyhydric alcohol having at least one alicyclic ring, or a compound containing a cyclohexene or cyclopentene ring, which is appropriately oxidized with hydrogen peroxide, peracid or the like. And cyclohexene oxide or cyclopentene oxide-containing compounds obtained by epoxidation with an agent. Representative examples of alicyclic epoxy resins include hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2- (3,4-epoxycyclohexyl-5,5- Spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexenedionoxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) ) Adipate, 3,4-epoxy-6-methylcyclohexyl-3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, di (3, 4-epoxycyclohexylme Le) ether, ethylenebis (3,4-epoxycyclohexane carboxylate), epoxy hexahydrophthalic acid dioctyl and epoxy hexahydrophthalic acid di-2-ethylhexyl and the like.

Further preferable examples of the aliphatic epoxy resin include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate. Typical examples thereof include diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, and diglycidyl ether of sorbitol. Hexaglycidyl ether of pentaerythritol, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, ethylene glycol, propylene glycol Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as glycerin, and diglycidyl esters of aliphatic long-chain dibasic acids. Furthermore, monoglycidyl ethers of higher aliphatic alcohols, phenol, cresol, butylphenol or monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these, glycidyl esters of higher fatty acids, epoxidized soybean oil, epoxystearic acid Butyl, octyl epoxystearate, epoxidized linseed oil, epoxidized polybutadiene and the like.

Examples of cationic polymerizable organic substances other than epoxy compounds include oxetane compounds such as trimethylene oxide, 3,3-dimethyloxetane, and 3,3-dichloromethyloxetane; oxolane compounds such as tetrahydrofuran and 2,3-dimethyltetrahydrofuran Cyclic acetal compounds such as trioxane, 1,3-dioxolan, 1,3,6-trioxanecyclooctane; cyclic lactone compounds such as β-propiolactone and ε-caprolactone; ethylene sulfide, thioepichlorohydrin Such thiirane compounds; 1,3-propyne sulfide, 3,3-
Thietane compounds such as dimethylthiethane; ethylene glycol divinyl ether, alkyl vinyl ether,
Vinyl ether compounds such as 3,4-dihydropyran-2-methyl (3,4-dihydropyran-2-carboxylate) and triethylene glycol divinyl ether; spiro ortho ester compounds obtained by reacting epoxy compounds with lactones; Examples include ethylenically unsaturated compounds such as vinylcyclohexane, isobutylene, polybutadiene and derivatives of the above compounds. These cationically polymerizable organic substances can be used alone or in combination of two or more kinds according to desired performance.

Particularly preferred among these cationically polymerizable organic substances are alicyclic epoxy resins having at least two or more epoxy groups in one molecule, and having cationic polymerization reactivity,
It shows good properties in terms of viscosity reduction, volume shrinkage, thermal stability, etc.

The heat-sensitive cationic polymerization initiator (b) constituting the thermosetting resin composition for stereolithography of the present invention is a compound capable of releasing a substance that initiates cationic polymerization by heating, and particularly, a Lewis acid by heating. Preferred are double salts which are onium salts which can be released.

As such an onium salt, a sulfonium salt represented by the following general formula (I) can be preferably exemplified.

Here, R ₁ and R ₂ in the above formula are the same or different substituted or unsubstituted hydrocarbon residues, and R ₁ and R ₂ may form a ring.

A is represented by the following general formula (II) or (III):
An allyl group or a tertiary aliphatic group substituted with at least one aliphatic group. A has a functional group such as an unsaturated bond group, an alkoxy group, a nitro group, a halogen group, a hydroxyl group, a carboxyl group, an ester group, an ether group, a cyano group, a carbonyl group, a sulfone group, and a thioether group. Can be.

(Where R _{3 to} R ₆ are a hydrogen atom or a substituted or unsubstituted aliphatic group, preferably an alkyl group, and at least one of R _{3 to} R ₆ is a substituted or unsubstituted aliphatic group, preferably Is an alkyl group, and R _{7 to} R ₉ are a substituted or unsubstituted aliphatic group, preferably an alkyl group, and any two of R _{7 to} R ₉ may form a ring . a non-nucleophilic anion, wherein MQ _m ^{- -)} further X (M of B,
P, Sb, As, Fe, Al, Sn, Zn, Ti or an atom selected from Cd,
Preferred are B, P, Sb, and As. Q is a halogen atom, and m is a number of 1 to 6).

Preferred non-nucleophilic anions include BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆
^- , SbF _6- ^{and the} like.

Other non-nucleophilic anions include those represented by the formula MQ _m-1 OH (wherein M, Q and m are the same as above).

Still other non-nucleophilic anions include perchlorate ion (ClO ₃ ⁻ ) and trifluoromethyl sulfite ion (CF ₃ SO
₃ ^-), fluorosulfonic acid ion (FSO ₃ ^-), toluenesulfonic acid ion, such as trinitrobenzene sulfonate ion.

Such sulfonium salts can be synthesized relatively easily, for example, by reacting the corresponding sulfide with a highly active alkyl halide to synthesize a sulfonium salt having a halogen anion, followed by HMQ _m , NaMQ _m , KMQ _m , NH ₄ MQ
_m (where M, Q, and m are the same as described above), and can be obtained by performing anion exchange, or directly reacting a sulfide with a mail wine reagent such as triethyloxonium tetrafluoroborate. By
It is also possible to synthesize in good yield.

When a tertiary aliphatic group is reacted with a sulfide, the reaction can be carried out under acidic conditions using the corresponding alcohol as a starting material to obtain a sulfonium salt.

Examples of the sulfonium salt represented by the general formula (I) include the following compounds.

Further, as the sulfonium salt other than the sulfonium salt represented by the general formula (I), the following compounds may be mentioned.

These (b) heat-sensitive cationic polymerization initiators can be used alone or in combination of two or more to obtain desired properties.

In the composition of the present invention, a plurality of (a) thermosetting cationically polymerizable organic substances are used as the thermosetting cationically polymerizable organic substance in order to obtain desired properties as a thermosetting resin composition for three-dimensional modeling. Can be used in combination.

In particular, (a) a thermosetting cationically polymerizable organic substance containing at least 40% by weight of an alicyclic epoxy resin having at least two epoxy groups in one molecule has good thermal reactivity and mechanical properties. It is excellent in strength and thermal stability and has a shrinkage of 3% or less, so that a very excellent thermosetting three-dimensional object forming system can be configured.

In the thermosetting resin composition for three-dimensional modeling of the present invention, (b) the heat-sensitive cationic polymerization initiator is used in an amount of 0.05 to 10 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of (a) the thermosetting cationically polymerizable organic substance. It can be added in the range of up to 6 parts by weight. At the time of addition, using an appropriate solvent, (b)
The heat-sensitive cationic polymerization initiator can be used by dissolving it in a solvent.

In the thermosetting resin composition for three-dimensional modeling of the present invention, a coloring agent such as a pigment or a paint, a defoaming agent, a leveling agent, a thickener, Agent,
Various resin additives such as antioxidants, silica, glass powder,
Fillers such as ceramic powders and metal powders, modifying resins and the like can be used in appropriate amounts.

In particular, in the case of a YAG laser, carbon black is used in the composition of the present invention to absorb laser light energy.
It is preferable to add 1 to 30 parts by weight to 100 parts by weight.

The viscosity of the thermosetting resin composition for three-dimensional modeling of the present invention is preferably 2000 cps or less at room temperature, more preferably 1000 cps or less. If the viscosity is too high, the working time will be poor because the molding time will be long.

The outline of the curing system of the thermosetting resin composition for three-dimensional modeling of the present invention is as follows.

The thermal energy source used for curing the thermosetting resin composition for three-dimensional modeling of the present invention requires convergence, and therefore an infrared laser is preferable.For example, from the viewpoint of good power conversion efficiency and high maximum output, YAG Infrared lasers such as a laser and a carbon dioxide laser can be used.

The method of forming a three-dimensional object is as follows: first, the thermosetting resin composition for three-dimensional modeling of the present invention is housed in a container, and the surface of the composition is irradiated with heat energy, while relatively moving the container and the light guide, By selectively supplying infrared light necessary for curing from the light guide, a cured layer having a desired cross-sectional shape is formed,
This is submerged at a certain depth below the composition liquid level, and the same curing is performed on the liquid layer of the uncured composition formed thereon,
This is repeated to form the entire three-dimensional object.

Since the thermosetting resin composition for three-dimensional modeling of the present invention is cured by a cationic polymerization reaction using infrared rays, depending on the type of the (a) thermosetting cationically polymerizable organic substance used, the composition may be irradiated with infrared rays. By heating to about 30 to 60 ° C, the cross-linking reaction can be effectively promoted, and the obtained molded article can be post-cured at a temperature of 50 to 150 ° C to provide more mechanical strength. An excellent shaped object of the above can be obtained.

〔Example〕

Hereinafter, typical examples of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples. In the examples, “parts” means parts by weight.

Example 1 (a) As a thermosetting cationically polymerizable organic substance, 3,4
100 parts of epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, (b) 3 parts of prenyltetramethylenesulfonium hexafluoroantimonate as a heat-sensitive cationic polymerization initiator, and 2 parts of carbon black are sufficiently mixed. The thermosetting resin composition for three-dimensional modeling of the invention was obtained.

A three-dimensional NC (numerical control) table on which a container for holding the resin composition is placed, a thermosetting three-dimensional object composed of a YAG laser (output 3 W, wavelength 1.06 μm), an optical system, and a control section mainly using a personal computer Using the system, a cone having a diameter of 12 mm, a height of 15 mm, and a thickness of 0.5 mm was formed from the thermosetting resin composition for three-dimensional modeling. This molded article had no distortion, an extremely low shrinkage of 1.8%, extremely high molding accuracy, and excellent mechanical strength. The build time was 60 minutes.

Example 2 (a) As a thermosetting cationically polymerizable organic substance, 3,4
-80 parts of epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 20 parts of butanediol diglycidyl ether, (b) 1 part of prenyltetramethylenesulfonium hexafluoroarsenate as a heat-sensitive cationic polymerization initiator, t-butyltetra One part of methylene sulfonium hexafluorophosphate and two parts of carbon black were sufficiently mixed to obtain a thermosetting resin composition for three-dimensional modeling of the present invention.

Using the thermosetting three-dimensional object system shown in Example 1, a bell-shaped object having a bottom surface diameter of 12 mm, a height of 10 mm, and a thickness of 0.5 mm was prepared from the thermosetting resin composition for three-dimensional object molding. did. This molded article had no distortion, a shrinkage of 2.5%, extremely high modeling accuracy, and excellent mechanical strength. In addition, since the composition had a very low viscosity of 150 cps (25 ° C.), it was easy to handle and had excellent curability with a YAG laser. The build time was 60 minutes.

Example 3 (a) As a thermosetting cationically polymerizable organic substance, 3,4-
Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 50 parts, bisphenol A diglycidyl ether 30 parts, triethylene glycol divinyl ether 20 parts, (b) crotyltetramethylenesulfonium hexafluoroantimony as a heat-sensitive cationic polymerization initiator 3 parts of the nitrate were sufficiently mixed to obtain a thermosetting resin composition for three-dimensional modeling of the present invention.

3D NC (Numerical Control) table with container for resin composition, CO ₂ gas laser (output 5W, wavelength 10.6μ)
m) and a thermosetting three-dimensional object system composed of a control unit having an optical system and a personal computer as a main unit.
When a cup-shaped molded product having a thickness of 9 mm, a height of 9 mm and a thickness of 0.5 mm was molded, no distortion was obtained, a shrinkage ratio of 3.0% and an excellent molding accuracy were obtained. In addition, the molding time was as short as 40 minutes by heating the molded article to 50 ° C. and using a CO ₂ gas laser having a large output.

Example 4 (a) As a thermosetting cationically polymerizable organic substance, 3,4
-80 parts of epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 20 parts of vinylcyclohexene oxide, (b) 3 parts of crotyltetramethylenesulfonium hexafluoroantimonate as a heat-sensitive cationic polymerization initiator, and carbon black as a filler Ten parts were sufficiently mixed to obtain a thermosetting resin composition for three-dimensional modeling of the present invention.

Using the thermosetting three-dimensional molded article system shown in Example 1, the above-described thermosetting resin composition for three-dimensional modeling was used to obtain a second example.
When I made the same bell-shaped model as above, there was no distortion,
With a shrinkage of 2.6%, a product excellent in mechanical strength, modeling accuracy, and surface smoothness was obtained. The build time was 60 minutes.

Comparative Example 1 100 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 5 parts of boron trifluoride monoethylamine complex were sufficiently mixed to obtain a thermosetting cationically polymerizable resin composition.

Using the thermosetting three-dimensional molded object system shown in Example 1, an attempt was made to produce a conical shaped object similar to that of Example 1 from the above composition, but this composition was thermally reactive with a YAG laser. Was inferior, delamination occurred, and the desired shaped article could not be obtained.

Comparative Example 2 100 parts of bisphenol A diglycidyl ether, 8 parts of dicyandiamide, and 0.5 part of benzyldimethylamine were sufficiently mixed to obtain a thermosetting cationically polymerizable resin composition.

Using the thermosetting three-dimensional molded object system shown in Example 1, an attempt was made to produce a conical shaped object similar to that of Example 1 from the above composition, but this composition was thermally reactive with a YAG laser. Was inferior, delamination occurred, and the desired shaped article could not be obtained. The viscosity is 12000 cps (25
° C), the workability was very poor.

〔The invention's effect〕

The effect of the present invention is to provide an optimal composition as a thermosetting resin composition for three-dimensional modeling. In particular, the thermosetting resin composition for three-dimensional modeling of the present invention has an extremely small volume shrinkage upon curing, generally 5% or less, and preferably 3% or less.

Furthermore, the thermosetting resin composition for three-dimensional modeling of the present invention has excellent curing sensitivity by heating, has a low viscosity, has a small volume shrinkage upon curing, and has excellent mechanical strength of a cured product. It has various good characteristics such as good self-adhesiveness and good curing characteristics in an oxygen atmosphere.

Continuation of the front page (56) References JP-A-2-75618 (JP, A) JP-A-59-33320 (JP, A) JP-A-60-84303 (JP, A) JP-A-61-211366 (JP, A) , A) (58) Fields studied (Int. Cl. ⁶ , DB name) C08F 2/00-2/60 C08L 63/00-63/10 C08G 59/68-59/72 C08G 85/00

Claims (1)

(57) [Claims] 1. An essential component (a) a thermosetting cationically polymerizable organic substance, and (b) a thermosensitive cationic polymerization initiator represented by the following general formula (I): [Wherein R ₁ and R ₂ are the same or different, substituted or unsubstituted hydrocarbon groups, and R ₁ and R ₂ may form a ring. A represents the following general formula (II) or (III) (Here, R _{3 to} R ₆ are a hydrogen atom or a substituted or unsubstituted aliphatic group, and at least one of R _{3 to} R ₆ needs to be a substituted or unsubstituted aliphatic group. R ₇
To R ₉ are a substituted or unsubstituted aliphatic group, and any two of R _{7 to} R ₉ may form a ring. ). Further X ^- is a non-nucleophilic anion. Step 1 of placing a thermosetting resin composition for three-dimensional modeling containing a sulfonium salt represented by the following formula in a container: curing by applying heat energy to the surface of the thermosetting resin composition for three-dimensional modeling to obtain a desired thickness Step 2 of obtaining a first cured product, Step 3 of forming a layer of a thermosetting resin composition for three-dimensional modeling on the first cured product, Three-dimensional modeling formed on the first cured product Step 4 of curing by applying thermal energy to the surface of the layer of the thermosetting resin composition to obtain a laminate in which a second cured product having a desired thickness is laminated on the first cured product, A method of forming a three-dimensional object, comprising: a step 5 of repeating steps 3 and 4 at least once.